The evolutionary expansion of nematode-specific glycine-rich secreted peptides

International Conference and Exhibition on Molecular Medicine and Diagnostics

August 24-26, 2015 London, UK

Muying Ying

Scientific Tracks Abstracts: J Mol Genet Med

Abstract :

We analyzed the glycine-rich secreted peptides (GRSPs) of 10 species genomes: Homo sapiens, Dani rerio, Drosophila
melanogaster, Caenorhabditis elegans, Caenorhabditis briggsae, Arabidopsis thaliana, Monosiga brevicollis, Saccharomyces
cerevisiae, Dictyostelium discoideum, and Guillardia theta. The number of Grsps in each genome was 4, 6, 53, 93, 78, 52, 0, 0, 5 and 0,
respectively. Interestingly, there were fewer Grsps in human genome than in D. discoideum genome, despite the greater complexity
of humans. The two nematode species C. elegans and C. briggsae possessed the highest abundance of Grsps, of which 98.7% were
orthologous. Mapping these Grsps strengthened clustering and illustrated the clear co-linearity between the chromosomes of the two
nematodes. In particular, most of Grsps were found on chromosome V: 44 of 93 C. elegans and 41 of 78 C. briggsae. A comparative
analysis of orthologous Grsps from other species resulted in the successful annotation of 17 C. elegans Grsps with DAVID and 21 C.
elegans and 3 C. briggsae Grsps with Blast2Go. This observation highlighted the nematode-specific expansion of Grsps originating
from tandem duplications during ecological adaptation of the two nematodes. The phenomenon goes against the general rule that
gene families also experience evolutionary expansion in abundance in increasingly complex species.